React Native - Bevitel

Szerző: Sallai András
Copyright © Sallai András, 2023
Licenc: CC Attribution-Share Alike 4.0 International
Web: https://szit.hu

Triangle

Terület TextInputban

import { StatusBar } from 'expo-status-bar';
import { useState } from 'react';
import { StyleSheet, Text, TouchableHighlight, View } from 'react-native';
import { TextInput } from 'react-native';
 
function calcTriangleArea(base, height) {
  return base * height / 2;
}
 
export default function App() {
  const [base, setBase] = useState('');
  const [height, setHeight] = useState('');
  const [area, setArea] = useState('');
  function startCalc() {
    let result = calcTriangleArea(base, height);
    setArea(result);
  }
  return (
    <View style={styles.container}>
      <Text>Triangle</Text>
      <Text>Háromszög területszámítás</Text>
 
      <Text>Alap</Text>
      <TextInput
      style={styles.input}
      onChangeText={base => setBase(base)}
      />
 
      <Text>Magasság</Text>
      <TextInput
      style={styles.input}
      onChangeText={height => setHeight(height)}
      />
 
      <TouchableHighlight
        style={styles.button}
        onPress={startCalc}
      >
        <Text style={styles.buttonText}>Számít</Text>
      </TouchableHighlight>
 
      <Text>Terület</Text>
      {/* TERÜLET */}
      <TextInput
      style={styles.input}
      onChangeText={area => setArea(area)}
      value={area}
      />
 
      <StatusBar style="auto" />
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'aqua',
    alignItems: 'center',
    justifyContent: 'center',
  },
  button: {
    backgroundColor: 'blue',
    marginTop: 10,
    padding: 10,
    borderRadius: 3,
 
  },
  butotnText: {
    color: 'white',
    paddingLeft: 10,
    paddingRight: 10,
    fontSize: 22,
  },
  input: {
    backgroundColor: 'white',
    height: 30,
  }
});

Terület Textben

App.js

import { StatusBar } from 'expo-status-bar';
import { useState } from 'react';
import { StyleSheet, Text, TouchableHighlight, View } from 'react-native';
import { TextInput } from 'react-native';
 
function calcTriangleArea(base, height) {
  return base * height / 2;
}
 
export default function App() {
  const [base, setBase] = useState('');
  const [height, setHeight] = useState('');
  const [area, setArea] = useState('');
  function startCalc() {
    let result = calcTriangleArea(base, height);
    setArea(result);
  }
  return (
    <View style={styles.container}>
      <Text>Triangle</Text>
      <Text>Háromszög területszámítás</Text>
 
      <Text>Alap</Text>
      <TextInput
      style={styles.input}
      onChangeText={base => setBase(base)}
      />
 
      <Text>Magasság</Text>
      <TextInput
      style={styles.input}
      onChangeText={height => setHeight(height)}
      />
 
      <TouchableHighlight
        style={styles.button}
        onPress={startCalc}
      >
        <Text style={styles.buttonText}>Számít</Text>
      </TouchableHighlight>
 
      <Text>Terület</Text>
      <Text>{area}</Text>
 
      <StatusBar style="auto" />
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'aqua',
    alignItems: 'center',
    justifyContent: 'center',
  },
  button: {
    backgroundColor: 'blue',
    marginTop: 10,
    padding: 10,
    borderRadius: 3,
 
  },
  butotnText: {
    color: 'white',
    paddingLeft: 10,
    paddingRight: 10,
    fontSize: 22,
  },
  input: {
    backgroundColor: 'white',
    height: 30,
  }
});

A gomb külön fájlban

Buttonjs

import React from 'react';
import { StyleSheet, Text, TouchableHighlight } from 'react-native';
 
const Button = (props) => {
    return (
        <TouchableHighlight
        style={styles.button}
        onPress={props.onPress}
        >
            <Text style={styles.buttonText}>Számít</Text>
        </TouchableHighlight>
 
    );
}
 
export default Button;
 
const styles = StyleSheet.create({
    button: {
        backgroundColor: 'blue',
        marginTop: 10,
        padding: 10,
        borderRadius: 3,
 
    },
    buttonText: {
        color: 'white',
        paddingLeft: 10,
        paddingRight: 10,
        fontSize: 22,
    },    
});

App.js

import { StatusBar } from 'expo-status-bar';
import { useState } from 'react';
import { StyleSheet, Text, TouchableHighlight, View } from 'react-native';
import { TextInput } from 'react-native';
import Button from './components/Button';
 
function calcTriangleArea(base, height) {
  return base * height / 2;
}
 
export default function App() {
  const [base, setBase] = useState('');
  const [height, setHeight] = useState('');
  const [area, setArea] = useState('');
  function startCalc() {
    let result = calcTriangleArea(base, height);
    setArea(result);
  }
  return (
    <View style={styles.container}>
      <Text>Triangle</Text>
      <Text>Háromszög területszámítás</Text>
 
      <Text>Alap</Text>
      <TextInput
      style={styles.input}
      onChangeText={base => setBase(base)}
      />
 
 
      <Text>Magasság</Text>
      <TextInput
      style={styles.input}
      onChangeText={height => setHeight(height)}
      />
 
      <Button onPress={startCalc} />
 
      <Text>Terület</Text>
      <Text>{area}</Text>
 
      <StatusBar style="auto" />
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'aqua',
    alignItems: 'center',
    justifyContent: 'center',
  },
 
  input: {
    backgroundColor: 'white',
    height: 30,
  }
});